The invention relates generally to a device and in particular to an implantable device for selectively opening and at least partially closing tubular organs of the body, for example the urethra.
Devices for that purpose, which may comprise for example a sleeve of elastomeric plastic material which fits around the organ, are known in the form of prostheses for dealing with urinary incontinence. Such devices are closure arrangements which act on the urethra and which, when the natural sphincter muscle fails, take over performing the function thereof. One such device is for example an implantable urinary incontinence prothesis which is produced in a cushion-like form for silicone rubber and silicone gel and which presses in sponge-like fashion against the urethra in such a way that the urethra is closed as long as a more substantial internal pressure does not occur. Therefore, that arrangement only provides for increasing the resistance to a discharge flow through the urethra, so that the bladder must overcome the respective resistance produced by the device, in order to be emptied. The flow passage cannot be opened and closed as desired.
Another known device is an implantable prosthesis wherein a sleeve which can be pumped up by means of a fluid is positioned around the urethra at the outlet from the bladder. Also implanted are two small pumps which can be operated through the skin, and a fluid reservoir. The sleeve can be filled with one pump, and thus put into the closure condition, while the other pump provides for emptying the sleeve, with the pressure fluid being conveyed into the reservoir. Both the expenditure in respect of the prosthesis itself and also the expenditure in regard to the implantation operation are high. The various components with their comparatively complicated constituent elements increase the danger of failure, which means that repairs become necessary, involving surgical intervention.
Finally, a form of prosthesis for male urinary incontinence is known (German Utility Model No. 79 28 052) wherein a sleeve which fits around the urethra makes it possible to close off the urethra by applying a pressure thereto. The sleeve, at least in a portion thereof, is of such a configuration that that portion can be put into a closure or an open position by a bending effect, with a low degree of spring-back resiliency. The sleeve preferably comprises implantable plastic material with a insert of a material, for example silver, which is easy to bend and which does not have spring-back resiliency. Although such prostheses have proved a success, they are frequently inadequate in particular in regard to the duration of the closure pressure.
Many different problems occur in devices of the kind set forth above, which are also known by the general term of a `sphincter`. More particularly, the device must be capable of performing the respectively required closing and opening function in a satisfactory manner, and easily and conveniently, without unacceptable pressures or other loadings on the respective organ and the area therearound occurring. Having regard to the fact that the device is to be implanted in the body, the amount of space that it requires must be small. Finally, it should be possible for the implantation operation to be carried out with the utmost simplicity, while the manufacturing cost should not be too high.